Psychometric evaluation of the Serbian version of the Stigma Scale of Epilepsy (SSE)

Abstract

Objective: To evaluate the psychometric properties of the Serbian-language version of the Stigma Scale of Epilepsy (SSE).

Methods: The sample consisted of 108 patients with epilepsy (PWE) (60.2 % were female, age range: 19-67 years) and 102 students (86.3 % were female, age range: 18-47 years). The study encompassed two phases: (1) translation of the SSE into Serbian using the back-translation technique, and (2) evaluation of reliability and construct validity of the Serbian-language version of SSE. In addition to the SSE, the PWE filled out a Neurological Disorders Depression Inventory for Epilepsy (NDDI-E), Patient Health Questionnaire-9 (PHQ-9), and Generalized Anxiety Disorder-7 (GAD-7). The socio-demographic and clinical variables were noted for each patient by the semistructured interview. Besides completing the SSE, the students were asked if they knew anyone with epilepsy. The reliability of the questionnaire was tested by assessing the internal consistency of the scale (Cronbach's α), while construct validity was assessed by factor analysis, method of known-groups validation, and correlation analysis.

Results: SSE demonstrates a satisfactory level of reliability in both samples, with Cronbach's α of 0.86 in the PWE sample and 0.90 in the student sample. Using exploratory factor analysis, four factors were identified in both samples, corresponding relatively well with the scale domains originally produced, with a few exceptions described. Adverse effects (AEs) of antiseizure medications (ASMs) and driving ability significantly influenced SSE scores, but there were no significant effects of other socio-demographic and clinical variables on epilepsy-related stigma in the PWE sample. In addition, depression severity significantly influenced SSE scores (based on NDDI-E cut-off score), with the SSE showing a positive association with PHQ-9 (r = 0.42, p < .001) and GAD-7 (r = 0.35, p < .001) as well. Regarding the student sample, the effects of personal knowledge of someone with epilepsy on SSE scores were found to be significant. Besides, students (M = 46.28, SD = 16.43) reported higher epilepsy-related stigma than patients (M = 40.66, SD = 17.01), t(208) = 2.43, p < .05, d = 0.34.

Conclusion: The Serbian version of the SSE has good psychometric properties and represents a useful tool for assessing epilepsy-related stigma in both patients and the general population.

Keywords: Epilepsy; Psychometric properties; SSE questionnaire; Stigma.